SU1004981A2 - Device for determination of parameters of automatic control system dynamic links - Google Patents

Description

The invention relates to a measurement technique and can be used to identify links of automatic control systems.

 , According to the main author. St. No. 499557, a device comprising an input source associated with the inputs of a dynamic link and an input converter, connected in series a first subtraction unit, a first key and a first integrator, a second key in series and a second integrator, a third key and a control unit, the corresponding outputs of which are connected to the control inputs of the input source and keys, the second subtraction unit is connected between the output of the first integrator and the input of the second key, the third subtraction unit is between the output of the second integrator and the input of the third key, three digital voltage dividers, the input of the first of them is connected to the output of the input signal converter, and the output to the subtractive input of the first subtraction unit, the inputs of the second and third digital voltage dividers are connected to the output

the output converter, and their inputs, respectively, with the subtractive inputs of the second and third subtraction units, the control pulse block, the switch and three reversible counters, whose inputs are connected to the corresponding outputs of the switch, and the outputs are connected to the control inputs of digital dividers

The 10 voltages, the inputs of the control pulse unit are connected with the second outputs of all keys, and its outputs with one input of the switch, with another input connected to the output of the control unit fl.

However, in the known device, the static transmission coefficient of the link is determined at one point of the characteristic, i.e. with one fixed. The value of the input signal and, as a result, when identifying links with a nonlinear static characteristic, there is a significant error in the determination of all parameters.

The purpose of the invention is to improve the accuracy of the device.

The goal is achieved by the fact that in the device for determining parameters

The 30 dynamic links of the automatic control systems are additionally connected in series with an analog-digital converter, a memory unit, an OR element, the output of which is connected to the 1 {control input of the first digital voltage divider, and the second input - to the output of the first-time counter and the ather input of the memory unit ti, the third input of which is connected to the third output of the control unit and to the installation input of the first reversible counter, the input of the analog-digital converter being connected to the output of the conversion tel input. The drawing shows the functional scheme of the proposed device. The device includes an input signal source 1, a dynamic link 2, an input signal converter 3, an output signal converter 4, a first digital voltage divider 5, a second digital voltage divider 6, a third voltage divider, a first subtraction unit 8, a second subtraction unit 9, the first key 10, the second key 11, the first integrator 12, the second integrator 13, the control pulse unit, the third subtraction unit 15, the third key 16, the commutator 17, the first reversible counter 18, the second reversible counter 1 the third reversing counter 2d, analog The digital converter 21, a memory unit 22, an OR gate 23, the control 24 blo,. The device works as follows. Dynamic Link 2 is described by a second-order differential equation + - y k (K} x, Where X and Y are the input and output signals of the dynamic evolution, a are constant parameters to be determined; k (x) is the nonlinear static characteristic of the dynamic The converters 3 and 4 of the input and output signals convert the X and y signals to voltages, X., W, where i and m, j are the conversion coefficients "In the first .cut, a piecewise linear approximation is made of nonlinear characteristic k ( x). For this, control block 24 generates a signal. The source of input signal 1, as well as using key 10, switches the output of subtraction unit 8 to input of control impulse unit 14. Input source 1 produces a signal X, for example, steps with such intervals that the transient in the link 2 has time to finish. Bloc 14 amplifies the error signal and, depending on its sign, sends pulses to one of the outputs, which in the first clock cycle through switch 17 are connected to control inputs of a reversible counter 18. Counter 18 controls the coefficient m transmit digital divider 5 voltage, As a result, during post nstva signal x is performed equality UBb, x (t.) K ,, - (. x) 1, 2,. . 1, the time to reach a steady state output at x x. const; (1 is the number of approximation points J K.. (X.) Is the transfer coefficient of the digital divider 5 voltage at time t-- defined by the expression C, N ,. where C. is a constant coefficient;, -. Is a digital code in the reversible counter 18 at the moment of time. At the moment of time c, the digital code in counter 18 is proportional to the value of the nonlinear static characteristic of link 2 for x x I. At the same time, analog-digital converter 21 converts the signal x to a digital code that is fed to the address input of block 22 memory, at the same time the signal from the control unit 24 events, allows writing to the block 22 of the contents of the counter 18 at a given address. Thus, after the first clock cycle in the memory block 22, an array of k () values is written to the corresponding address values that approximate the nonlinear static characteristic of the dynamic link 2, In the second clock cycle, block 24 The control unit transfers the memory unit 22 to the read mode and, via the installation input, resets the reversible counter 18 pulses to the zero state. At the same time, the input signal is generated, the output of the block .8 is connected via the switch 10 to the output of the integrator 12, and the output of the block 9 via the switch 11 is connected to the output of the control pulse block 14, the outputs of which are switched to the inputs of the reversible counter 15 via the coupler 17.

At the same time, the input signal x can be arbitrary with the condition that after time t ty, the output signal y will take a steady state. When the input signal changes, x analog-to-digital converter 21 Vfabatyat address codes that are used to read the codes corresponding to k (x) which, through the OR circuit 23, enters the digital divider 5 voltage.

Thus, the nonlinear characteristic k (x) is dynamically simulated for Even 2, the integrator 12 integrates the difference of signals (x) x, and its output voltage is, -t

U;, (t) "(

Through time t 7 /. ty, derivative of Ory with y (o) y (o) O. we have

,)

B.)

The control circuit of the transmission coefficient Kj of the digital voltage divider 6 fulfills the equality

1 (and).)

from (1) follows

and Na,

where Cd is a constant coefficient; M, j - code in the counter 19 J

T is located at the time of the integrator 12.

In the third cycle, control block 24 switches the output of block 9 through key 11 to input of integrator 13, and output of block 15 through key 16 is connected to input of block 14, the output of Copioro is switched to input of reversible counter 20 via switch 17. Reverse counter 19 is in mode the storage code, the reversible counter 18 is in the zero state, and the differential voltage divider B is controlled by the memory unit 22.

The control of the coefficient K 3 of the digital divider 7 for example, occurs until equality is reached.

SIJ "., K)

)

where (is the output voltage of the integrator 13.

Consequently,

o-b where C, is a constant coefficient;

T is the time constant of integrator 13; - the code in the counter 20,

N,

Thus, after three cycles, the parameters Zp and a of the linear part of the transfer function of the dynamic link 2 are determined by the digital codes N and N in the respective reversible counters. The approximation parameters of the nonlinear static characteristic are determined by the numeric codes (i, ... t) in the Pampti block 22.

Thus, the proposed device makes it possible to take into account the nonlinear static characteristic of the dynamic link and thereby increase the accuracy of determining all its parameters.

F. formula

A device for determining the parameters of the dynamic links of automatic control systems by aut. St. No. 499557, characterized in that, in order to increase accuracy, it contains a serially connected angular digital converter, a memory block, an OR element whose output is connected to the control input of the first digital voltage divider, and the second input to the output of the first reversible counter and to the second block input

memory, the third input of which is connected to the third output of the control unit and to the installation input of the first reversible counter, the input of the analog-digital converter

connected to the output of the input converter.

Sources of information taken into account in the examination 1. USSR author's certificate

 499557, cl. G 05 23/02, 1976 (prototype).

Claims (1)

Claim A device for determining the parameters of the dynamic links of automatic control systems according to ed. St. No. 499557, characterized in that, in order to increase accuracy, it contains a series-connected analog-to-digital converter, a memory unit, an OR element 40, the output of which is connected to the control input of the first digital voltage divider, and the second input to the output of the first reversible counter and to the second input of the memory unit 45, the third input of which is connected to the third output of the control unit and to the installation input of the first reversible counter, and the input of the analog-digital converter 5Q is connected to the output of the input Nogo signal.